Abstract
BACKGROUND: Iron overload from chronic transfusion therapy can be extremely toxic and most patients (pts) do not receive adequate iron chelation therapy (ICT) despite evidence of transfusional iron overload (IOL). Deferasirox (DFX) is the principal option currently available for ICT in the management of IOL due to transfusion dependent anemia, such as in MDS pts. The most common adverse events (AEs) are gastrointestinal disorders, skin rash, elevations in liver enzymes levels and non-progressive transient increases in serum creatinine also in MDS pts, most of whom are elderly with significant comorbidities and side effects of other concomitant therapies. In order to achieve effective ICT with minimal toxicity in individual pts, regular monitoring to assess IOL and adverse effects of DFX treatment is essential.
METHODS: The safety and efficacy of DFX were examined in a retrospective multicenter observational study of transfusion-dependent (TD) MDS pts with International Prognostic Scoring System (IPSS) low-or Int-1-risk. We included all pts treated with DFX up to 12 months, divided into two groups; the first one (group A) not under a multidisciplinary assessment, including pts not adequately treated, in terms of dosing and discontinuation of ICT and the second one (group B) with pts under multidisciplinary control. The DFX starting dosing was 10 mg/kg/die in all pts. The aim of our retrospective analysis was to assess the effectiveness of ICT in relation of dosing and right management of AEs.
RESULT: We evaluated 45 MDS pts (12F/33M); 27 belonging to the group A and 18 to group B. The age was 74.2±8.8 and 77.3±4.8 respectively. The ECOG 0-1 was 85,1% in group A and 88,9% in group B. The transfusion episodes prior starting DFX were22.1±12.1 and 24.5±35.4 in the first and in the second group, respectively. The serum ferritin level at baseline was respectively 1285.1±489.6 ng/mL and 1452.6±748.1 ng/mL. The mean serum ferritin level increased from 1285.1+489.6 ng/mL to 1412.1+842.8 ng/mL in group A while decreased from 1452.6+748.1 ng/mL to 1166.1+ 723.4 ng/mL in group B. The rate of inadequate therapy, in terms of dosing and/or discontinuation ICT, was 85% in group A compared to 60% in group B (p= 0.086).The rate of severe SAE observed in all pts was 10%.The most common AEs were diarrhea, nausea, upper abdominal pain, serum creatinine increase. The positive hematological response rate was observed in 15% of all pts.
CONCLUSIONS: The study showed that group B obtained advantage in terms of efficacy and toxicity. The difference between the two groups derived from the ability to manage comorbidities, concomitant therapies and AEs, in particular the rise in serum creatinine, the most common cause DFX discontinuation or dosing reduction. In this setting, the most important specialist was the nephrologist. In our multidisciplinary group experts in management of ICT were hematologist, internist, immune-hematologist and nephrologist. We shared how we monitored kidney function and managed a possible nephrotoxicity (table.2), in order to ensure DFX efficacy. Positive hematological responses were observed, and a subset of pts achieved transfusion independence. The timing of future multidisciplinary evaluation is set on 24 and 36 months, time in which we expect the best response to DFX therapy.
Table 1. Ferritin trend group A (n27) group B (n18) Ferritin N mean±SD Median (range) N mean±SD Median (range) Baseline 27 1285.1±489.6 1134 (388-2099) 18 1452.6±748.1 1515 (160-3018) 3 months 22 1451.5±720.5 1247.5 (529-2791) 13 1312.7±909.8 1064 (521-3859) 6 months 23 1850.5±1079.1 1419 (374-4185) 11 1168.4±648.4 1300 (160-2409) 12 months 17 1412.1±842.8 1372 (111-3127) 9 1166.1±723.4 930 (277-2536)
Table 2. Management of renal changes during therapy with DFX Creatinine and urine examination:1) in two successive determinations prior to initiation of therapy, then every month 2) in pts with other risk factors for kidney disease, every week for 1 month after start of DFX or dose increase and, subsequently, every month Changes in creatinine:1) increased by 33% in two successive determinations: reduce DFX dose of 5 mg/kg 2) progressive increase of creatinine: interrupt DFX and then re-challenge it at a lower dose with gradual increase if the clinical benefits outweigh the risks
Disclosures
No relevant conflicts of interest to declare.
BETA THALASSEMIA MAJOR;
